Tube Systems; Implantation - MIETHKE miniNAV Mode D'emploi

miniNAV
valve in the proximal inlet of the reservoir.
By this mechanism, flow in the direction of
the ventricular catheter is avoided during the
pumping procedure. The opening pressure
of the shunt system is not increased by the
implantation of the CONTROL RESERVOIR.
WARNING
Frequent pumping can lead to overdrainage
and thus to pressure conditions outside
the normal physiological range. The patient
should discuss the risks (involved) with their
surgeon.
Tight tolerancing of the deflector ensures
a good fit with the ventricular catheter. By
adjusting the deflector (prior to implantation)
the length of catheter penetrating into the skull
can be optimised. The ventricular catheter is
"deflected" at a right angle in the burr hole.

TUBE SYSTEMS

The miniNAV has been designed to ensure the
optimal ventricular pressure. It is available as
a shunt system or as individual valve units
with or without an integrated distal catheter
(internal diameter 1.2 mm, external diame-
ter 2.5 mm). Individual valve units should be
used with catheters of approx. 1.2 mm internal
diameter and approx. 2.5 mm external diam-
eter. The connector on the valve allows using
catheters of 1.0 mm to 1.5 mm internal diam-
eter. The external diameter of the catheter
should be about double the internal diameter.
Regardless, the catheters must be fixed care-
fully, with a ligature, to the valve connectors.
It is essential that kinks in the catheter are
avoided. The included catheters have virtually
no effect on the pressure-flow characteristics.

IMPLANTATION

Positioning the ventricular catheter
Several surgical techniques are available for
positioning the ventricular catheter. The nec-
essary skin incision should be carried out,
preferably, in the shape of a lobule pedicled
towards the draining catheter or as a straight
skin incision. To avoid CSF leakage, care
should be taken that the dura opening is kept
as small as possible after applying the burr
hole. The ventricular catheter is stiffened by
INSTRUCTIONS FOR USE | GB
the introducing stylet supplied with the prod-
uct.
The miniNAV is available in different shunt
variations:
When using a miniNAV with a Burrhole Reser-
voir or SPRUNG RESERVOIR, the ventricu-
lar catheter is implanted first. Once the intro-
ducing stylet has been removed, the patency
of the ventricular catheter can be tested by
checking if CSF is dripping out. The catheter
is shortened and the Burrhole Reservoir is
connected, with the connection secured with
a ligature. The skin incision should not be
located directly above the reservoir. The mini-
NAV with Prechamber or CONTROL RESER-
VOIR comes with a deflector. This deflector
is used for adjusting the position of deflec-
tion before implanting the ventricular catheter.
The catheter is deflected; the Prechamber is
put into place. The position of the ventricular
catheter should be inspected again by post-
operative CT or MR imaging.
Positioning the miniNAV
The miniNAV should be implanted in the head
of the patient. The valve is marked with an
arrow pointing to distal (downwards) to indi-
cate the flow direction. Whether the label
faces towards the skin or the brain is of
no importance in terms of the valve's per-
formance. Following subcutaneous tunneling,
the catheter is either pushed from the burr
hole, possibly through a reservoir, to the
selected valve implantation site; or it is pushed
through from the valve and connected to the
reservoir, if there is any.
Positioning the peritoneal catheter
The access site for the peritoneal catheter
is left to the surgeon's discretion. It can be
applied e. g. para-umbilically in a horizontal
direction or transrectally at the height of the
epigastrium.
Likewise, various surgical techniques are
available for positioning
catheter. We recommend pulling through the
peritoneal catheter, using a subcutaneous
tunneling tool and perhaps with an auxiliary
incision, from the shunt to the intended posi-
tion of the catheter. The peritoneal catheter,
which is usually attached securely to the mini-
NAV, has an open distal end, but no wall
the peritoneal
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